2019/03/15 by P. N. Appleton, Philip Appleton, L. Armus +62
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Astrophysics of Galaxies (astro-ph.GA) #FOS: Physical sciences #Galaxies: Formation, Evolution, Phenomena #astro-ph.GA
paper · pdf · doi:10.48550/arxiv.1903.06653
Submitted as a science White Paper to the Astronomy and Astrophysics Astro 2020 Decadal Survey call issued by the National Academies of Sciences, Engineering and Medicine (March 11 2019)
arxiv created 2019/03/15 · openalex publication_date 2019/03/15 · arxiv updated 2019/03/18 · openalex created_date 2019/03/22 · openalex updated_date 2026/07/28
Galaxy formation depends on a complex interplay between gravitational collapse, gas accretion, merging, and feedback processes. Yet, after many decades of investigation, these concepts are poorly understood. This paper presents the argument that warm H2 can be used as a tool to unlock some of these mysteries. Turbulence, shocks and outflows, driven by star formation, AGN activity or inflows, may prevent the rapid buildup of star formation in galaxies. Central to our understanding of how gas is converted into stars is the process by which gas can dissipate its mechanical energy through turbulence and shocks in order to cool. H2 lines provide direct quantitative measurements of kinetic energy dissipation in molecular gas in galaxies throughout the Universe. Based on the detection of very powerful H2 lines from z = 2 galaxies and proto-clusters at the detection limits of \it Spitzer, we are confident that future far-IR and UV H2 observations will provide a wealth of new information and insight into galaxy evolution to high-z. Finally, at the very earliest epoch of star and galaxy formation, warm H2 may also provide a unique glimpse of molecular gas collapse at 7 < z < 12 in massive dark matter (DM) halos on their way to forming the very first galaxies. Such measurements are beyond the reach of existing and planned observatories.